FIG. 5 is a fragmentary side elevation showing a conventional television receiver. A picture tube 1 is housed in a cabinet 2 having an opening 25 in its front side. The opening-defining edge of the cabinet 2 is opposed to a lower end portion of the picture tube 1 with a clearance M formed therebetween. The cabinet 1 has a front wall provided with a power key 9. A first circuit board 6 opposed to the power key 9 is disposed on the rear side of the front wall and has a switch 8 which is to be pressed by the power key 9. The picture tube 1 is turned on or off by the switch 8.
Provided below the picture tube 1 is a second circuit board 3 which has mounted thereon a known deflection circuit and a synchronization circuit, and radiating plates 30, 30 for preventing overheating of these circuits. The second circuit board 3 is away from the first circuit board 6 and connected thereto by a bundle of electric wires (not shown).
The surface of the picture tube 1 is susceptible to soiling in the case of television receivers, especially those having a display of large size which has gained popularity in recent years. If seriously soiled, the picture tube 1 will be cleaned by wiping with use of a liquid cleaner or water. In such an event, it is likely that the liquid cleaner or waterdrops 4 adhering to the surface of the receiver 1 will flow down the surface and fall onto the inside bottom wall of the cabinet 2 through the clearance M between the tube 1 and the cabinet 2. The amount of dripping cleaner or water, although small, is sufficient to cause an electrical failure to the electronic components on the second circuit board 3.
With the conventional receiver, however, the second circuit board 3 is a sufficient distance away from the front wall of the cabinet 2 and is therefore unlikely to be exposed to the dripping cleaner or water.
It is required in recent years to reduce the thickness of television receivers of the type described, i.e., to give a shortened depth to the cabinet 2. To meet the requirement, there arises a need to position the second circuit board 3 closer to the front side of the cabinet 2.
Further from the viewpoint of a reduction in the number of components and a lower cost, a proposal has already been made on an arrangement wherein the first circuit board 6 is absent. FIG. 6 shows the proposed arrangement, in which an elastically deformable connector 97 is used for attaching the power key 9 directly to the rear side of the cabinet 2, and the switch 8 to be pressed by the key 9 is mounted on a circuit board 3. This arrangement also requires that the circuit board 3 be positioned closer to the front side of the cabinet 2.
The positioning of the circuit board 3 toward the front then involves the likelihood that the cleaner or water 4 flowing down the surface of the picture tube 1 will drip onto the circuit board 3, permitting the electronic components on the board 3 to malfunction electrically.
Incidentally, the present applicant has previously proposed provision of protective walls 7, 7, serving as a roof, between the picture tube 1 and the circuit board 3 as shown in FIG. 7, so that the waterdrops 4 produced on the rear side of the picture tube 1 by condensation will be prevented from falling onto the circuit board 3 (see Published Japanese Utility Model Registration No. 23191/1987). Accordingly, it appears also useful to provide such a protective wall 7 below the picture tube 1 as indicated in a dot-and-dash line in FIG. 6.
Nevertheless, the condensed water 4, when running along the bottom surface of the picture tube 1, will not always drip at a definite location, but is likely drip onto the board 3, clearing the protective wall. Thus, the wall fails to perfectly protect the electronic components on the circuit board 3.